The invention pertains to automated robotic welding systems, and more particularly, to self-contained welding stations.
Dedicated work areas, frequently referred to as xe2x80x9cwork cellsxe2x80x9d or xe2x80x9cwork stationsxe2x80x9d are well known in the industrial arts. Particularly in the area of welding, the use of such work cells or work stations is common, because of the benefits associated with the strict enclosure of the welding operation, and isolation of the welding operation from the surrounding industrial environment.
Work cells or work stations equipped with robots are also well known. See, for example, U.S. Pat. No. 4,695,027, issued to Lindholm, and U.S. Pat. No. 6,274,839 B1, issued to Stone.
One of the drawbacks associated with prior art welding stations, in particular, has been the necessity for secure mounting of the robot head in relation to the workpiece to be welded. Conventional wisdom teaches that the robot head must be securely mounted to the factory floor, or to the base of the work cell or work station. While overhead mounted robots have been successfully used in certain applications, such as that taught by Cahlander in U.S. Pat. No. 4,922,435, there remains a need for a self-contained welding-type work station wherein the robotic head is mounted integrally to the work station and above the stage within the station where the welding operation will take place. This methodology provides the benefit of creating a unitary and transportable work station which is compact, preserving precious industrial floor space, yet still allowing the entire assembly to be positioned, installed, and if necessary, relocated within the industrial environment.
The invention is an automated welding system utilizing overhead mounted robots within a self-contained and repositionable work station. The invention utilizes a xe2x80x9cshuttlexe2x80x9d work table system, which includes one or more tables which shuttle to and from a position adjacent to the operating elements associated with the robotic arm. The invention incorporates overhead mounting of the robot directly over the operating stage, thereby drastically reducing the required floor space. The application can be used with either single or multiple robotic arm assemblies.
Further, the invention incorporates a structure forming an enclosure and supporting a robotic arm assembly. The robotic arm assembly is designed to operate within an operating stage served by one or more shuttling tables. An automated welding operation takes place within the confines of the enclosure, which protects the surrounding area from the byproducts of welding, protects nearby workers from those byproducts, and encloses the potentially dangerous light emissions from the welding process.
The welding equipment itself may be any of the conventional arc, MIG, TIG, or other common welding techniques readily adaptable to robotic tools.
The work station is built upon a sturdy perimeter frame comprised of one or more elements, including a ceiling frame, a floor frame and side wall frames. Side wall frames are provided with covers which form the enclosure. The covers themselves may be equipped with one or more openings, likewise provided with shutters. Mounted to the outside of the enclosure are one or more power supplies and one or more enclosures for operating elements such as motors, sensors, controllers, computers and the like
The welding robotic arm assembly is conventional in all respects, and may have either fixed or movable track mounting. Likewise, the robotic arm assembly may utilize a turntable mounting, including a base rotor assembly which is positionable using a drive system and having appropriate feedback means, typically utilizing stepper motors. The robot arm has one or more articulating joints for selective positioning of the robot arm in all three axes within the enclosure, as well as rotating joint elements. The end of the robot arm is provided with a welding tool appropriate to the welding task to be performed. Utilizing the positioning features above described, the robot arm can be positioned in any predetermined location about the operating stage.
The shuttle tables are provided with bearing surfaces to accommodate sliding table elements. The sliding elements have a top, bottom, side and ends and are positionable on the bearing surfaces by appropriate drive means having associated feedback means.
In operation, one or more work pieces are positioned in predetermined locations on one or more work tables. Work tables are automatically positioned utilizing the aforedescribed drive means to the operating stage. Program logic or machine vision software, or both, provide instructions to the robot for correct positioning of the robot operating elements in relation to the workpiece and performing of the welding operations.